The present invention relates to rubber mixtures with improved processing behavior and high filler activity, containing 1,4-butenediol and/or 1,4-butenediol polyether, as well as the use of the rubber mixtures for the production of vulcanizates, in particular for the production of highly reinforced, abrasion-resistant molded articles, and preferably for the production of tires that have a low rolling resistance and a high abrasion resistance.

Patent
   6815484
Priority
Jul 18 2001
Filed
Jul 15 2002
Issued
Nov 09 2004
Expiry
Jul 15 2022
Assg.orig
Entity
Large
10
22
EXPIRED
1. Rubber mixtures comprising at least one rubber, 0.05 to 25 parts by weight with respect to 100 parts by weight of employed rubber, of butenediol polyether corresponding to the structure
wherein
R1 and R2 independently of one another denote hydrogen or a C1 to C4 alkyl radical, and
n and m independently of one another denote integers from 0 to 10 with the proviso that n and m cannot at the same time be 0,
and 1 to 500 parts by weight of filler with respect 100 parts by weight of employed rubber.
2. A rubber mixture according to claim 1, wherein said n and m, independently of one another denote integers from 0 to 5.
3. Vulcanizates and rubber molded articles comprising a rubber mixture according to claim 1.
4. Vulcanizates and rubber molded articles according to claim 3, wherein said vulcanizate and rubber molded article is a tire or tire component.

The present invention relates to rubber mixtures that contain, in addition to at least one rubber, also 1,4-butenediol and/or 1,4-butenediol polyether as well as fillers, as well as the use of the rubber mixtures for the production of vulcanizates, in particular for the production of highly reinforced, abrasion-resistant molded articles, more preferably for the production of tires that have a low rolling resistance and a high abrasion resistance.

A number of proposed solutions have been elaborated for producing tires having a reduced rolling resistance. Specific polysulfide silanes as reinforcing additives for silicic acid-containing rubber vulcanizates have been described in DE-A-2 255 577 and 4 435 311, EP-A1 0 670 347 as well as U.S. Pat. No. 4,709,065. However, a disadvantage of the use of the polysulfide silanes described there as reinforcing additives for silicic acid-containing rubber vulcanizates is that relatively large amounts of the expensive polysulfide silanes have to be used in order to achieve an acceptable compatibility.

In order to improve the processing of silicic acid-containing rubber mixtures, further additives have been proposed such as fatty acid esters, fatty acid salts or mineral oils. The aforementioned additives have the disadvantage that they raise the flowability but at the same time reduce the tensile modulus values at relatively large elongation (e.g. 100% to 300%), with the result that the reinforcing action of the filler is impaired.

It has also been known to add polyalcohols and polyglycols to rubber mixtures. For example, rubber mixtures that contain specific polyethylene oxides are described in EP-A1 0 869 145 and EP-A1 0 738 755. The structures of the polyethers used are not disclosed. According to the teaching of the specified documents the aforementioned polyethylene oxides scarcely improve the processability of the unvulcanized rubber mixtures, but affect in particular the properties of the vulcanizates, in particular the antistatic properties and the abrasion behavior.

Rubber mixtures containing specific 1,2-diols and 1,3-diols are known from EP-A 761 734. These rubber mixtures containing 1,2-diols and 1,3-diols tend however to stick to the roller and have an adverse effect on the mechanical properties of the vulcanizates.

Accordingly, the object of the present invention was to provide additives that, inter alia, improve the flowability of rubber mixtures without however reducing the activity of the fillers contained in the mixtures, and to provide vulcanizates having good properties, in particular with respect to abrasion, rolling resistance and wet anti-skid properties in tires.

It has now been found that 1,4-butenediol and 1,4-butenediol polyethers significantly improve the flowability of rubber mixtures and lead to vulcanizates having a good reinforcing behavior, favorable dynamic damping and good abrasion behavior.

Accordingly, the present invention provides rubber mixtures containing at least one rubber, 0.05 to 25 parts by weight with respect to 100 parts by weight of employed rubber, of 1,4-butenediol or 1,4-butenediol polyether or mixtures thereof, the butenediol polyether corresponding to the structure

wherein

R1 and R2 independently of one another denote hydrogen or a C1 to C4 alkyl radical, preferably methyl or ethyl, and

n and m independently of one another denote integers from 0 to 10, preferably 0 to 5, with the proviso that n and m cannot at the same time be 0,

as well as 1 to 500 parts by weight of filler referred to 100 parts by weight of employed rubber.

Preferably, butenediols or their polyethers are used that contain 0.1 to 10 moles of ethylene oxide and/or propylene oxide per hydroxyl group, more preferably 0.7 to 7 moles of ethylene oxide and/or propylene oxide per mole of hydroxyl groups, and that have molecular weights in the range from 88 to 1500, preferably in the range from 88 to 700. Most preferably, the corresponding polyethers are based on cis-1,4-butenediol. The production of such addition products and polyaddition products of 1,4-butenediol is known in the prior art and is described for example in Houben-Weyl, Methoden der Organischen Chemie, Vol. XIV/2, Thieme Verlag, Stuttgart, 1963 pp. 436-440 and p. 450. Such polyethers are also commercially available and, depending on their production, are preferably used as a mixture of the corresponding polyethylene oxides and polypropylene oxides. Preferably, the rubber mixtures according to the present invention contain the 1,4-butenediol or its polyether of the above formula in amounts of 0.3 to 15 parts by weight, in particular, in amounts of 0.5 to 6 parts by weight, most preferably in amounts of 1 to 5 parts by weight.

The rubbers to be used for the production of the rubber mixtures according to the present invention include natural rubber and synthetic rubbers. Preferred synthetic rubbers are for example described in W. Hofmann, Kautschuktechnologie, Genter Verlag, Stuttgart 1980. These synthetic rubbers include, inter alia

BR-- polybutadiene
ABR-- butadiene/acrylic acid C1-C4 alkyl ester copolymers
CR-- polychloroprene
IR-- polyisoprene
SBR-- stirene/butadiene copolymers with stirene contents in the
range from 1 to 60 wt. %, preferably in the range from 20 to
50 wt. %
IIR-- isobutylene/isoprene copolymers
NBR-- butadiene/acrylonitrile copolymers with acrylonitrile contents
in the range from 5 to 60 wt. %, preferably in the range from
10 to 40 wt. %
HNBR-- partially hydrogenated or completely hydrogenated NBR
rubber
EPDM-- ethylene/propylene/diene copolymers

as well as mixtures of these rubbers.

Mixtures of, in particular, natural rubber, emulsion SBR rubber as well as solution SBR rubber and polybutadiene rubber are of importance in the production of vehicle tires. Of particular interest is the use of solution SBR rubbers with a vinyl content in the range from 20 to 60 wt. % as well as polybutadiene rubbers with a high 1,4-cis content (>90%) that have been produced using catalysts based on nickel, cobalt, titanium and/or neodymium, as well as polybutadiene rubber with a vinyl content of up to 75 wt. % as well as the mixtures of the aforementioned solution SBR and polybutadiene rubbers. Most preferred are corresponding solution SBR and polybutadiene rubbers with an additional content of bound functional groups, in particular hydroxyl and/or carboxyl groups. Preferred contents of hydroxyl and/or carboxyl groups are in the range from 0.05 to 3 wt. % with respect to the rubber. More preferred rubbers according to the present invention are described, for example, in German patent applications DE-A1 19 832 549, DE-A1 19 852 648, DE-A1 19 914 848, DE-A1 19 920 788, DE-A1 19 920 814 as well as DE-A 2 653 144 and EP A1 0 464 478.

Furthermore, the rubber mixtures according to the present invention preferably contain 5 to 300 parts by weight of fillers. Particularly suitable as fillers are oxidic and/or silicate fillers and/or carbon blacks. Oxidic and/or silicate fillers are preferred.

The following suitable oxidic and/or silicate fillers are preferably used:

Highly dispersed silicic acid produced, for example, by precipitating solutions of silicates or by flame hydrolysis of silicates, silicon halides with specific surfaces in the range from 5 to 1000 m2/g, preferably in the range from 20 to 400 m2/g (BET surface) and with a primary particle size in the range from 10 to 400 nm. The silicic acids may optionally also be present as mixed oxides with other metal oxides such as Al, Mg, Ca, Ba, Zn, Zr, Ti oxides.

Synthetic silicates such as aluminum silicate, alkaline earth silicates such as magnesium silicate or calcium silicate with BET surfaces in the range from 20 to 400 m2/g and primary particle diameters in the range from 10 to 400 nm.

Natural silicates such as kaolin and other naturally occurring silicic acids.

Glass fibers and glass fiber products (mats, strands) or micro glass spheres.

Metal oxides such as zinc oxide, calcium oxide, magnesium oxide, aluminum oxide.

Metal carbonates such as magnesium carbonate, calcium carbonate, zinc carbonate.

Metal hydroxides such as aluminum hydroxide, magnesium hydroxide.

As has already been mentioned, carbon blacks are also suitable as fillers. These carbon blacks are produced by the lampblack, furnace or carbon black process and generally have BET surfaces of 20 to 200 m2/g, such as for example SAF, ISAF, HAF, FEF or GPF carbon blacks.

A mixture of 10 to 100 parts by weight of oxidic and/or silicate fillers and 5 to 50 parts by weight of carbon black, with respect to 100 parts by weight of employed rubber, are preferably used as fillers in the rubber mixtures according to the present invention.

For the production of rubber vulcanizates, the known and conventional rubber auxiliary substances may also be added to the rubber mixtures according to the present invention, in particular vulcanization accelerators, anti-aging agents, heat stabilizers, light stabilizers, ozone stabilizers, processing auxiliary substances, plasticizers, tackifiers, blowing agents, dyes, pigments, waxes, extenders, organic acids, retarding agents, metal oxides, crosslinking agents as well as activators. In this connection, reference may be made to I. Franta, Elastomers and Rubber Compounding Materials, Elsevier 1989, pp. 325-494.

The rubber auxiliary substances are used in conventional amounts that are governed by, inter alia, the intended use. Conventional amounts are, for example, amounts in the range from 0.1 to 50 wt. % referred to the total amount of employed rubbers.

Furthermore, the known crosslinking agents such as sulfur, sulfur donors or peroxides may also be used in the production of rubber vulcanizates. Vulcanization accelerators such as mercaptobenzthiazoles, guanidines, thiuranes, dithiocarbamates, thioureas and/or thiocarbonates may obviously also be added to the rubber mixtures according to the present invention. The vulcanization accelerators and crosslinking agents are used in amounts in the range from 0.1 to 10 wt. %, preferably in the range from 0.1 to 5 wt. %, with respect to the total amount of employed rubbers.

In a more preferred embodiment, the rubber mixtures according to the present invention contain, besides the aforementioned rubbers, fillers, 1,4-butenediol and/or 1,4-butenediol polyether, rubber auxiliary substances and crosslinking agents, also sulfur-containing silyl ethers as filler activators in an amount ranging from 0.5 to 15 parts by weight with respect to 100 parts by weight of employed rubbers, in particular bis-(trialkoxysilylalkyl)-polysulfides as described in DE-A-2 141 159 and DE-A-2 255 577, and/or oligomeric and/or polymeric sulfur-containing silyl ethers as described in DE-A-4 425 311 and EP-A1-0 670 347, and/or mercaptoalkyl trialkoxy silanes such as mercaptopropyltriethoxy silane, and/or thiocyanatoalkylsilyl ethers, as described in DE-A-1 9 544 469.

The rubber mixtures according to the present invention may be produced in the conventional types of apparatus such as mixing units, in particular rollers, internal mixers and mixer-extruders.

The vulcanization of the rubber mixtures according to the present invention may normally take place at temperatures in the range from 100°C to 200°C C., preferably in the range from 130°C to 180°C C., optionally at pressures in the range from 10 to 200 bar.

The rubber mixtures according to the present invention containing 1,4-butenediol and/or 1,4-butenediol polyether are characterized in particular by a good flowability, high processing reliability as well as improved vulcanization kinetics, and provide vulcanizates with high tensile modulus values. The rubber mixtures are, therefore, particularly suitable for the inexpensive production of highly reinforced, corrosion-resistant molded articles, in particular tires and tire components.

The following may, in particular, be mentioned as molded articles: cable sheathings, hoses, drive belts, conveyor belts, roller coatings, tires, shoe soles, sealing rings and damping elements. The rubber mixtures according to the present invention are most preferably used for producing tire treads with low rolling resistance.

The polyethers based on 1,4-butenediol can be produced according to the instructions given in Houben-Weyl, Methoden der Organischen Chemie, Vol. XIV/2, Thieme Verlag, Stuttgart, 1963, pp. 436-440, 450. The specified amounts refer to parts by weight.

The following rubber mixtures were produced in a 1.5 l capacity internal mixer (70 rpm, starting temperature 80°C C., 5 minutes' mixing time). At the end of the mixing time, sulfur and accelerators were then mixed in on a roller (temperature: 50°C C.).

TABLE
Comparison Example
A 1
L-SBR BUNA VSL 5025-1 (oil extended 96 96
rubber from Bayer AG)
BR rubber Buna CB24 (Bayer AG) 30 30
Vulkasil ® S (precipitated silicic acid from 80 80
Bayer AG)
Russ Corax ® N 339 6.5 6.5
Silan Si ® 1849-1 (aromatic mineral oil 8 8
from BP)
ZnO 2.5 2.5
Stearic acid 1 1
Vulkanox ® 4020 (Bayer AG) 1 1
Ozone protection wax Antilux ® 654 1.5 1.5
(Rheinchemie)
4.2 × propoxylated cis-1,4-butenediol, mean 0 4
molecular weight 330, OH number 340,
viscosity 60 cP at 25°C C.
Sulfur 1.5 1.5
Vulkacit ® CZ (sulfenamide accelerator from 1.5 1.5
Bayer AG)
Vulkacit ® D (diphenylguanidine accelerator 2 2
from Bayer AG)
Mixing viscosities ML 1 + 4 at 100°C C.: 99 88
Mooney prevulcanization in minutes, 17.1 19.5
t5/130°C C. (DIN 53.523)
Rheovulcameter (180°C C./90 bar/3 minutes), 0.74 1.1
volume in ml
Vulcanization at 160°C C./28 minutes
Tensile strength (MPa) 18.8 19.6
Elongation at break (%) 386 413
Tensile modulus value at 300% elongation 12.9 13.9
(MPa)
Rebound elasticity at 23°C C. (%) 32 32
Tear-propagation resistance in N/mm (DIN 53 36.9 53.5
515)
Abrasion in ccm (DIN 53 516) 75 77
Shore hardness A at 23°C C. 68 68

Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.

Scholl, Thomas, Weidenhaupt, Hermann-Josef

Patent Priority Assignee Title
10508187, Apr 29 2009 Tundra Composites, LLC Inorganic material composite
11041060, Apr 29 2009 Tundra Composites, LLC Inorganic material composite
11767409, Apr 29 2009 MORGAN, FRED Reduced density hollow glass microsphere polymer composite
8487034, Jan 18 2008 Tundra Composites, LLC Melt molding polymer composite and method of making and using the same
8841358, Apr 29 2009 Tundra Composites, LLC Ceramic composite
9105382, Nov 14 2003 Tundra Composites, LLC Magnetic composite
9153377, Jan 18 2008 Tundra Composites, LLC Magnetic polymer composite
9249283, Apr 29 2009 Tundra Composites, LLC Reduced density glass bubble polymer composite
9376552, Apr 29 2009 Tundra Composites, LLC Ceramic composite
9771463, Apr 29 2009 TUNDRA COMPANIES Reduced density hollow glass microsphere polymer composite
Patent Priority Assignee Title
3842111,
3873489,
3978103, Aug 17 1971 Deutsche Gold- und Silber-Scheideanstalt vormals Roessler Sulfur containing organosilicon compounds
4076550, Aug 17 1971 Deutsche Gold- und Silber-Scheideanstalt vormals Roessler Reinforcing additive
4343339, Sep 06 1978 Bayer Aktiengesellschaft Process for the production of tires comprising vulcanized elastomers containing urethane groups
4709065, Sep 20 1985 Shin-Etsu Chemical Co., Ltd. Organosilicon compound having polysulfide linkages and a rubber composition comprising the same
4766252, Oct 16 1987 ISP 3 CORP; ISP Investments Inc Solvent and stain resistant coatings
5565275, Sep 21 1993 Evonik Degussa GmbH Process for the production of composite articles of polyesters and elastomers
5663226, Mar 03 1994 Bayer AG Rubber mixtures containing reinforcing additives, which additives include sulphur and silicon
5703151, Apr 17 1995 Sumitomo Chemical Company, Limited Rubber composition
5717022, Sep 07 1995 Rhein Chemie Rheinau GmbH Rubber composition, particularly for tire tread
6130277, Mar 31 1997 Nestec S A Rubber composition improved in anti-static property and pneumatic tire using the same
6174951, Apr 22 1997 Bayer Aktiengesellschaft Surface-modified, oxidic or silicated filling materials and the use thereof
6251976, Apr 01 1998 Bayer Aktiengesellschaft Rubber mixtures containing trimethylopropane distillation residues
6268421, Oct 01 1994 Degussa AG Reinforcement additives
20010031822,
CA2186060,
DE19914848,
DE19929788,
GB1575115,
JP2003105140,
WO9847955,
///
Executed onAssignorAssigneeConveyanceFrameReelDoc
Jun 21 2002SCHOLL, THOMAS DECEASED LEGAL HEIRS ULRIKE SCHOLL, PHILIPP SCHOLL, CHRISTINE SCHOLL, AND JOHANNES SCHOLL MINORS Bayer AktiengesellschaftASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS 0131670542 pdf
Jun 28 2002WEIDENHAUPT, HERMANN-JOSEPHBayer AktiengesellschaftASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS 0131670542 pdf
Jul 15 2002Bayer Aktiengesellschaft(assignment on the face of the patent)
Date Maintenance Fee Events
May 19 2008REM: Maintenance Fee Reminder Mailed.
Nov 09 2008EXP: Patent Expired for Failure to Pay Maintenance Fees.


Date Maintenance Schedule
Nov 09 20074 years fee payment window open
May 09 20086 months grace period start (w surcharge)
Nov 09 2008patent expiry (for year 4)
Nov 09 20102 years to revive unintentionally abandoned end. (for year 4)
Nov 09 20118 years fee payment window open
May 09 20126 months grace period start (w surcharge)
Nov 09 2012patent expiry (for year 8)
Nov 09 20142 years to revive unintentionally abandoned end. (for year 8)
Nov 09 201512 years fee payment window open
May 09 20166 months grace period start (w surcharge)
Nov 09 2016patent expiry (for year 12)
Nov 09 20182 years to revive unintentionally abandoned end. (for year 12)